Vulnerability details
CVE-2026-11404
Cesanta Mongoose
Cesanta Mongoose Out-of-Bounds Read in MG_TLS_BUILTIN ClientHello Session ID Parsing
CVSS 4.0
8.7High
Official description
Cesanta Mongoose before 7.22 contains an out-of-bounds read in the built-in TLS server function mg_tls_server_recv_hello(), which uses an attacker-controlled session_id_len byte from a TLS ClientHello as a buffer index without validating it against the length of received data. A remote, unauthenticated attacker can send a single crafted ClientHello with an oversized session id length to read past the receive buffer, crashing any HTTPS, MQTTS, or WSS service built on MG_TLS_BUILTIN.
CVSS scores
| Score | Version | Source | Vector |
|---|---|---|---|
| 8.7High | 4.0 | CVEProject cvelistV5 (CNA) (VulnCheck) | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N |
| 7.5High | 3.1 | CVEProject cvelistV5 (CNA) (VulnCheck) | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected products
| Vendor | Product | Versions | Source |
|---|---|---|---|
| Cesanta | Mongoose | v < 7.22 | CVEProject cvelistV5 (CNA) |
References and advisories
3
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Details
- Published
- 2026-07-09
- Last updated
- 2026-11-03
- State
- Published
- Assigner (CNA)
- VulnCheck
Exploit prediction (EPSS)
0.78%
Probability of exploitation in 30 days
56.2%
Percentile (among all CVEs)
SSVC assessment (CISA)
- Automatable
- Yes
- Exploitation
- None
- Technical impact
- Partial
Weaknesses (CWE)
- CWE-125Out-of-bounds Read